The ‘multimammate rat’ called Mastomys natalensis which has many breasts and lives in the bush and around residential areas is the reservoir host of Lassa fever.
The virus is shed in the urine and droppings of the rats, hence can be transmitted through direct contact, touching objects or eating food contaminated with these materials or through cuts or sores.
The onset of the disease is usually gradual, starting with fever, general weakness, muscle and joint pains, prostration, and malaise.
After a few days, headache, sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough and abdominal pain may follow.
In severe cases facial swelling, fluid in the lung cavity, bleeding from the mouth, nose, vagina or gastrointestinal tract and low blood pressure may develop; shock, seizures, tremor, disorientation and coma and death may be seen in the later stages.